Add const sections

6 files changed, 59 insertions, 1 deletions

diff --git a/include/elna/boot/ast.h b/include/elna/boot/ast.h
index 8f8da13..c12d8e8 100644
--- a/include/elna/boot/ast.h
+++ b/include/elna/boot/ast.h
@@ -111,6 +111,7 @@ namespace elna::boot
     class variable_declaration;
     class procedure_declaration;
     class type_declaration;
+    class constant_declaration;
     class procedure_call;
     class cast_expression;
     class record_constructor_expression;
@@ -154,11 +155,15 @@ namespace elna::boot
      */
     struct block
     {
+        std::vector<constant_declaration *> constants;
         std::vector<variable_declaration *> variables;
         std::vector<statement *> statements;
         /// Scope containing the variables, entered by the name analysis.
         std::shared_ptr<symbol_table> symbols;
 
+        block(std::vector<constant_declaration *>&& constants,
+                std::vector<variable_declaration *>&& variables,
+                std::vector<statement *>&& statements);
         block(std::vector<variable_declaration *>&& variables, std::vector<statement *>&& statements);
         block(const block&) = delete;
         block(block&& that) noexcept = default;
@@ -175,6 +180,7 @@ namespace elna::boot
     struct parser_visitor
     {
         virtual void visit(variable_declaration *) = 0;
+        virtual void visit(constant_declaration *) = 0;
         virtual void visit(procedure_declaration *) = 0;
         virtual void visit(type_declaration *) = 0;
         virtual void visit(procedure_call *) = 0;
@@ -235,6 +241,7 @@ namespace elna::boot
         [[noreturn]] void visit(extern_type_expression *) override;
 
         [[noreturn]] void visit(variable_declaration *) override;
+        [[noreturn]] void visit(constant_declaration *) override;
         [[noreturn]] void visit(procedure_declaration *) override;
         [[noreturn]] void visit(assign_statement *) override;
         [[noreturn]] void visit(if_statement *) override;
@@ -284,6 +291,7 @@ namespace elna::boot
         void visit(extern_type_expression *) override;
 
         void visit(variable_declaration *) override;
+        void visit(constant_declaration *) override;
         void visit(procedure_declaration *) override;
         void visit(assign_statement *statement) override;
         void visit(if_statement *statement) override;
@@ -748,6 +756,22 @@ namespace elna::boot
     };
 
     /**
+     * Constant definition.
+     */
+    class constant_declaration : public declaration
+    {
+    public:
+        const identifier_definition identifier;
+        expression *const initializer;
+
+        constant_declaration(const source_position position, identifier_definition identifier,
+                expression *initializer);
+        ~constant_declaration() override;
+
+        void accept(parser_visitor *visitor) override;
+    };
+
+    /**
      * Cast expression.
      */
     class cast_expression : public expression
diff --git a/include/elna/boot/materialization.h b/include/elna/boot/materialization.h
index 74b4133..7436c45 100644
--- a/include/elna/boot/materialization.h
+++ b/include/elna/boot/materialization.h
@@ -30,7 +30,8 @@ namespace elna::boot
             real_overflow,
             local_export,
             local_extern,
-            variable_generic
+            variable_generic,
+            constant_generic
         };
 
         materialization_error(const source_position position, kind error_kind);
@@ -52,6 +53,7 @@ namespace elna::boot
         void visit(unit *unit) override;
         void visit(procedure_declaration *declaration) override;
         void visit(variable_declaration *declaration) override;
+        void visit(constant_declaration *declaration) override;
 
         void visit(literal<integer_literal> *literal) override;
         void visit(literal<float_literal> *literal) override;
diff --git a/include/elna/boot/name_analysis.h b/include/elna/boot/name_analysis.h
index 62b91b4..1d9676a 100644
--- a/include/elna/boot/name_analysis.h
+++ b/include/elna/boot/name_analysis.h
@@ -200,6 +200,7 @@ namespace elna::boot
         void visit(unit *unit) override;
         void visit(type_declaration *declaration) override;
         void visit(variable_declaration *) override;
+        void visit(constant_declaration *) override;
         void visit(procedure_declaration *) override;
     };
 
@@ -351,6 +352,8 @@ namespace elna::boot
         std::filesystem::path redefinition_file(const std::shared_ptr<info>& original) const;
         std::shared_ptr<variable_info> register_variable(const std::string& name,
                 const type& variable_type, const source_position position, const bool is_extern = false);
+        std::shared_ptr<constant_info> register_constant(const std::string& name,
+                const type& constant_type, const constant_value& value, const source_position position);
         std::optional<type> lookup_pointer_like_field(const std::string& field_name,
                 const type& element_type);
         type lookup_field(const type& composite_type, const std::string& field_name);
@@ -436,6 +439,7 @@ namespace elna::boot
         void visit(unit *unit) override;
         void visit(type_declaration *declaration) override;
         void visit(variable_declaration *declaration) override;
+        void visit(constant_declaration *declaration) override;
         void visit(procedure_declaration *declaration) override;
 
         [[noreturn]] void visit(for_statement *) override;
@@ -456,6 +460,7 @@ namespace elna::boot
         void visit(unit *unit) override;
         void visit(type_declaration *) override;
         void visit(variable_declaration *declaration) override;
+        void visit(constant_declaration *declaration) override;
         void visit(procedure_declaration *declaration) override;
 
         void visit(for_statement *statement) override;
diff --git a/include/elna/boot/symbol.h b/include/elna/boot/symbol.h
index bdac269..190a297 100644
--- a/include/elna/boot/symbol.h
+++ b/include/elna/boot/symbol.h
@@ -277,6 +277,7 @@ namespace elna::boot
     class procedure_info;
     class variable_info;
     class label_info;
+    class constant_info;
 
     class info : public std::enable_shared_from_this<info>
     {
@@ -292,6 +293,7 @@ namespace elna::boot
         virtual std::shared_ptr<procedure_info> is_procedure();
         virtual std::shared_ptr<variable_info> is_variable();
         virtual std::shared_ptr<label_info> is_label();
+        virtual std::shared_ptr<constant_info> is_constant();
     };
 
     /**
@@ -514,6 +516,29 @@ namespace elna::boot
     };
 
     /**
+     * Constant symbol information.
+     */
+    class constant_info : public info
+    {
+    public:
+        /// Constant type.
+        const type symbol;
+
+        /// Evaluated constant value.
+        const constant_value value;
+
+        /**
+         * Constructs constant symbol information.
+         *
+         * \param symbol Constant type.
+         * \param value Evaluated constant value.
+         */
+        constant_info(const type& symbol, const constant_value& value);
+
+        std::shared_ptr<constant_info> is_constant() override;
+    };
+
+    /**
      * Named block a break-statement can jump to.
      */
     class label_info : public info
diff --git a/include/elna/boot/validation.h b/include/elna/boot/validation.h
index 2af68e0..028b0dd 100644
--- a/include/elna/boot/validation.h
+++ b/include/elna/boot/validation.h
@@ -59,6 +59,7 @@ namespace elna::boot
         void visit(unit *unit) override;
         void visit(type_declaration *declaration) override;
         void visit(variable_declaration *) override;
+        void visit(constant_declaration *) override;
         void visit(procedure_declaration *declaration) override;
 
         void visit(case_statement *statement) override;
diff --git a/include/elna/gcc/elna-generic.h b/include/elna/gcc/elna-generic.h
index f942f81..6fc395e 100644
--- a/include/elna/gcc/elna-generic.h
+++ b/include/elna/gcc/elna-generic.h
@@ -82,6 +82,7 @@ namespace elna::gcc
 
         void visit(boot::type_declaration *) override;
         void visit(boot::variable_declaration *declaration) override;
+        void visit(boot::constant_declaration *declaration) override;
         void visit(boot::procedure_declaration *) override;
         void visit(boot::procedure_call *call) override;
         void visit(boot::cast_expression *expression) override;